Multiple vortex waste separator apparatus

ABSTRACT

A multiple vortex separator for drawing a substantially moisture-free airstream from a waste stream having an annular channel defining a first vortex flow path for separating liquid and solid waste from this waste stream and an inverted conical cavity between nested inverted cones defining a second vortex flow path that is isolated from the first vortex flow path for separating additional liquid and solid waste from the waste stream before it exits the vortex separator.

FIELD OF THE INVENTION

This invention pertains to systems for separating aircraft waste and,more particularly, to a multiple vortex apparatus for removing solid andliquid waste from a waste stream from aircraft toilets or otherreceptacles while withdrawing a substantially moisture-free airstreamunder suction.

BACKGROUND OF THE INVENTION

Various systems are available in the art that employ a vacuum totransport liquid and solid waste material from aircraft toilets or otherreceptacles to a waste tank for storage. The waste material that istransported includes solid human waste, urine, water, optionallycleansing and disinfecting chemicals, air, toilet paper, food, and oftenunexpected discarded items, all of which are drawn from the aircrafttoilets or other receptacles to one or more waste tanks. The wastetanks, of course, are emptied during ground servicing of the aircraft.

The suction that transports the waste material to a waste tank isusually provided by a vacuum generator when the aircraft is on theground or at low altitudes. At higher altitudes, the system typicallywill be vented to the external lower pressure atmosphere, creating apressure differential between the exterior atmosphere and the interiorof the aircraft to draw the waste material from the aircraft toilets orother receptacles for transport to the waste tank for storage.

As the waste material is transported to the waste tank, the air whichwas drawn along with the waste material must be released to theatmosphere. This air must be free of moisture and particulate solids forsanitary and for safety reasons. As to sanitary concerns, it isobviously undesirable to release particulate human waste into theatmosphere, either when the aircraft is airborne or when it is on theground. Additionally, there is a danger that if a substantial amount ofwater escapes the aircraft from such a vacuum driven aircraft wastecollection system, it may build up on the aircraft fuselage to form ice.

Conventional aircraft waste material separation systems are large and sorequire excessive space in the aircraft while contributing unnecessarilyto the aircraft weight, reducing its fuel efficiency. Also, conventionalwaste material separation systems require frequent servicing, which isoften difficult and time-consuming to perform because of inconvenientaccess to the separator apparatus. Additionally, conventional wastematerial separation systems typically have two separators, one at theinlet and another at the outlet of the systems. Finally, conventionalseparation apparatus, while often effective in removing moisture fromthe waste material under optimal conditions, could nevertheless beimproved by ensuring that the apparatus consistently prevents the escapeof moisture.

Thus, the need exists for an improved waste material separation systemusing a single separator making for an overall system that is compactand lightweight without compromising its performance. It should also beconsistently effective in minimizing or preventing the escape ofmoisture in the outgoing airstream. Additionally, the apparatus must becapable of being easily and safely replaced with minimal exposure to thecollected waste. Finally, the apparatus should also be capable of beingeasily installed in the limited space available in the aircraft. Thepresent invention satisfies all of these requirements and has otherbenefits as well.

BRIEF SUMMARY OF THE INVENTION

The present invention comprises a multiple vortex separator for drawinga substantially moisten-free airstream from a waste stream containingliquid and solid waste. The separator is particularly well adapted foruse in aircraft. The separator of the invention includes a housing,which is preferably cylindrical in shape, and has a waste inlet forreceiving the waste stream. The top of the cylindrical housing isenclosed and has an exhaust port for drawing the substantiallymoisture-free airstream from the housing by way of suction forceprovided by a vacuum generator or, at high altitudes, the pressuredifferential between the exterior atmosphere and the interior of theaircraft.

An annular channel is positioned along the inner surface of thecylindrical wall of the housing. This channel defines a first vortexpath for separating liquid and solid waste from the waste stream. Theannular channel is in communication with the waste inlet.

A pair of nested inverted cones is located within the cylindricalhousing. These cones define an inverted conical cavity that is incommunication with the exhaust port. A second vortex flow path whichforms within the conical cavity thus is isolated from the first vortexpath.

Accordingly, a waste stream containing liquid and solid waste is drawninto the housing through the waste inlet by a suction force applied tothe exhaust port. The entering waste stream encounters the annularchannel along the inner surface of the housing wall, moving in a firstvortex flow path in which liquid and solid wastes are separated from thewaste stream by centrifugal force. As a result, the heavier wastematerials move to the outside of the annular channel and fall downwardlyfor collection as appropriate. The remaining lighter airstream entersthe inverted conical cavity between the nested cones in a second vortexpath that is isolated from the first vortex path. Additional liquid andsolid waste is removed from the airstream moving through the conicalcavity again by centrifugal force to produce a substantiallymoisture-free airstream which exits from the vortex separator throughthe exhaust port. The source of suction will be either the cabin toatmosphere differential at high altitudes or a vacuum generator at lowaltitudes.

In a preferred embodiment, radially disposed vanes are positionedadjacent the entrance of the conical cavity. These vanes are angledabout their radial axes to form angled slots for inducing and enhancingrotary motion in the airstream passing through the slots into theconical cavity.

The inner surface of the inner cone defines an inner conical chamber. Abarrier extends between the cones forming a top closure of the conicalcavity. Finally, at least one interconnecting port is located in thistop closure communicating between the conical cavity and the innerconical chamber. Thus, the airstream moving through the separator passesfrom the conical cavity into the inner conical chamber through theinterconnecting port.

The inner conical chamber may have a check valve at its bottom adaptedto open when the separator is not drawing a waste stream into thecylindrical housing. When this happens, liquid and solid waste that hascollected in the inner conical chamber will fall from the chamber to becollected as appropriate. Also, a filter medium may be disposed in thechamber to coalesce moisture remaining in the airstream that passesthrough the chamber.

Finally, an exhaust member may be generally centered in the conicalchamber. The exhaust member has an annular shelf positioned above thechamber and the top closure of the cones. It also has a central tubularportion projecting downwardly into the chamber defining an exit conduitleading from the chamber to the top of the cylindrical housing of theseparator. Thus, the airstream exiting the chamber will pass through thetubular portion before being removed from the top of the housing via theexhaust port. Finally, a demister filter may be disposed across the topopening of the tubular portion to help remove any remaining moisture inthe exiting airstream.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to aid in understanding the invention, it will now be describedin connection with exemplary embodiments thereof with reference to theaccompanying drawings in which like numerical designations will be givento like features with reference to the accompanying drawings wherein:

FIG. 1 is a perspective view of the exterior of a waste tank fitted witha vortex separator in accordance with the present invention;

FIG. 2 is a partial cut-away view of the vortex separator and waste tankof FIG. 1; and

FIG. 3 is an enlarged view of the vortex separator of FIG. 1.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

The embodiment of the invention described below is not intended to beexhaustive or to limit the invention to the precise structure andoperation disclosed. Rather, the embodiment described in detail belowhas been chosen and described to explain the principles of the inventionand its application, operation and use in order to best enable othersskilled in the art to follow its teachings.

Turning now to FIG. 1, the exterior of a waste tank 10 having a multiplevortex waste separator 12 in accordance with the invention isillustrated. The vortex separator 12 includes a housing 14 that ispreferably cylindrical as shown and an exhaust cap 16 with an exhaustport atop the housing. The exhaust cap may be removably clamped to thetop of the cylindrical housing to permit access to the interior of theseparator when desired. Exhaust tube 18 will be connected as showndiagrammatically to a source of suction comprising a vacuum generator 22at low altitudes or the external atmosphere at high altitudes 24 to drawwaste from aircraft toilets or other receptacles by way of the vortexseparator. The switching is achieved with an altitude-sensitive bypasscheck valve 20.

Vortex separator 12 has an inlet tube 26 which in an aircraft functionsto transport the waste stream from an aircraft toilet or otherreceptacle to the separator. The inlet tube thus, e.g., receives a wastestream comprising air, waste water, waste solids, and other materialsfrom the aircraft toilet when it is flushed. This stream, which isrepresented diagrammatically by arrow WS1, is drawn into vortexseparator 12 by suction provided either by the pressure differential athigh elevations or by the operation of a vacuum generator at lowaltitudes applied at exhaust tube 18. The vacuum generator preferablywill produce a vacuum of about 3-9 inches Hg. At an altitude of about16,000 feet, the system will switch from the vacuum generator to thecabin-to-atmosphere differential by way of the operation of check valve20 to draw the waste stream into the separator. Finally, waste tank 10includes a drain tube 28 at its bottom which will be connected to awaste removal port on the outside of the aircraft (not shown) throughwhich waste collected in tank 10 will be drained during servicing of theaircraft.

As can be seen in the cut-away view of FIG. 2 which illustrates theinternal structure of vortex separator 12, the vortex separator includesan annular channel 30 in communication with inlet tube 26 formed intoinner wall 31 of annular wall 32 of cylindrical housing 14. It should benoted that the lower portion 33 of wall 32 extends into waste tank 10with an outer annular lip 35 encircling the outer surface 37 of the wallresting on a corresponding lip 29 of the tank so that the two may beremovably clamped together (FIG. 1).

Thus, the vacuum applied at exhaust tube 18 is transmitted across thevortex separator to draw stream WS1 into inlet tube 26 under highvelocity. This high velocity stream is directed by inlet tube 26 intoannular channel 30 which defines a first vortex flow path V1. As streamWS1 moves in flow path V1 a lighter airstream WS2 migrates to the centerof the separator cylindrical housing as most of the heavier solids andliquids move to the outside and fall out of stream WS1 to the bottom ofwaste tank 10.

The next important feature is an inverted truncated conical cavity 34between an inner inverted cone 36 nested within an outer inverted cone38. Thus, the inner surface 37 of outer inverted cone 38 and the outersurface 39 of inner inverted cone 36 define inverted conical cavity 34which is generally centered within housing 14. Nested cones 36 and 38are mounted below exhaust cap 16, and are interconnected by a supportstructure 40 at the entrance to the conical cavity having vanes 41extending radially outwardly from a hub 43. The vanes are angled abouttheir radial axes to form angled slots for inducing rotary motion in theairstream passing through the slots into conical cavity 34 to the secondvortex path. Support structure 40 maintains the spacing between thecones without obstructing passage of material from the conical cavity inthe space between the vanes. A funnel 47 is located below the nestedcones. The outer surface 51 of the funnel helps divert the lighterairstream WS2 into inverted conical cavity 34.

The nested truncated cones also define an annular opening 45 (FIG. 3)along their bottom edge into which airstream WS2 is drawn, and fromwhich heavier material will fall from conical cavity 42 past vanes 41 aswill be explained in more detail below. Finally, the top edge of thenested cones is generally closed off by an annular top closure 44 whichhas a port 46 through which air may be transported from the conicalcavity. A second like port is located 180° opposite port 44 but ishidden in the Figures.

Airstream WS2 therefore is drawn up through the conical cavity by thesuction force applied at exhaust tube 18. Due to the nesting of thecones this stream can only travel between the walls of the cones. As aresult of the fan-like strut structure, the conical shape of cavity 34,and the high velocity, stream WS2 will move through cavity 34 in asecond vortex flow path V2 which, as can be seen in FIG. 2, is isolatedfrom vortex flow path V1. Vortex flow path V2 again produces acentrifugal force that causes remaining heavier materials (particulatewaste & liquid) to move to the outside where it will fall down throughconical cavity 42 and annular opening 45 at the bottom of the nestedcones into tank 10. Meanwhile, the remaining lighter airstream WS3 willpass upwardly through port 46 in top closure 44 to be drawn down into aninner inverted truncated conical chamber 50 defined by the inner surface48 of cone 36.

A waste check valve 60 is located at the bottom 54 of chamber 50. Thischeck valve comprises an inverted umbrella-shaped rubber membrane 52supported below strut structure 56 by a central upwardly projectinglocking member 58 that is mounted in a hole at the center of the strutstructure. The check valve allows solids and liquids to fall fromtruncated conical chamber 50 to funnel 47 and out bottom funnel opening49 to waste tank 10 but does not allow contaminated air from below thecheck valve to enter the chamber, as explained below. As is illustrateddiagrammatically in FIG. 3, chamber 50 also contains a first filtermaterial 62 which helps coalesce remaining moisture as the stream movesthrough truncated conical chamber 50 to leave a further portion of wastestream WS3 with at most minimal amounts of moisture as it exits chamber50.

Stream WS3 next enters an exhaust member 63 having an annular shelf 64resting at the top of cone 36 and a tubular portion 66 centered abovechamber 50, with tubular portion 66 extending partially into the chamberand the annular flange supporting the exhaust member across the top ofthe nested cones. Shelf 64 rests below exhaust cap 16 of the vortexseparator. Preferably, a demister filter material 72 is disposed acrossthe top opening 72 of tubular portion 66 to trap moisture and helpdemist entrained moisture moving past the mesh through cap 16 and outexhaust tube 18. Both filter materials 62 and 72 preferably are in theform of a dense knitted mesh of metal, nylon or propylene. Thus, filtermaterial 72 is positioned to remove most if not all of the moistureremaining in stream WS3, so that the airstream moving out throughexhaust tube 18 to the outside atmosphere will be free of moisture.

The device will operate when the flush cycle of the airplane toilet isinitiated. When this happens, waste stream WS1 will be drawn from thetoilet through inlet tube 26 into annular channel 30 and first vortexflow path V1 in which the resulting centrifugal force causes the heaviercomponents of the waste mixture to move to the outside and fall intowaste tank 10, as discussed earlier.

Meanwhile, a remaining rapidly moving vortex comprising stream WS2enters inverted truncated conical cavity 34 through the angled slotsbetween vanes 41 and the remaining solids and water are furtherseparated by the centrifugal force produced in a second vortex flow pathV2 causing additional solids and water to fall into waste tank 10,leaving remaining waste stream WS3 as an airstream substantially free ofsolids and with a substantially reduced level of liquids. WS3 is thendrawn from the center of the separator cylindrical housing into conicalcavity 34 through port 46 along annular channel 55 of closure 44 andinto inverted conical chamber where it passes up through first filtermaterial 62 which helps coalesce entrained liquid in stream WS3 so thatit accumulates and falls to the bottom of the inverted conical chamber.As a result, when the vacuum in the system is no longer applied, checkvalve 60 will open under the weight of the accumulated material at thebottom of chamber 50 so that this waste material can move past the checkvalve into funnel 47 from which it will fall through bottom funnelopening 49 to the bottom of tank 10 joining the earlier separated waste.

It should be noted that vortices V1 and V2 do not intersect. This is animportant feature of the invention since intermingling of crossing highvelocity waste streams moving through the vortices would causeadditional particulate moisture and solids to be formed significantlyreducing the effectiveness of the separator.

Finally, the remaining stream WS3 passes from exhaust chamber tubularportion 66 of exhaust member 63 through demister filter 72 where itpasses through exhaust cap 16 into exhaust tube 18 to either the vacuumgenerator or the atmosphere if the aircraft is operating at a highaltitude. Typically, the above process, from the application of thevacuum through the completion of the separation process will take about1 to 4 seconds.

All references, including publications, patent applications, andpatents, cited herein are hereby incorporated by reference to the sameextent as if each reference were individually and specifically indicatedto be incorporated by reference and were set forth in its entiretyherein.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. Recitation of ranges of values herein are merely intended toserve as a shorthand method of referring individually to each separatevalue falling within the range, unless otherwise indicated herein, andeach separate value is incorporated into the specification as if it wereindividually recited herein. All methods described herein can beperformed in any suitable order unless otherwise indicated herein orotherwise clearly contradicted by context. The use of any and allexamples, or exemplary language (e.g., “such as”) provided herein, isintended merely to better illuminate the invention and does not pose alimitation on the scope of the invention unless otherwise claimed. Nolanguage in the specification should be construed as indicating anynon-claimed element as essential to the practice of the invention.

Preferred embodiments of this invention are described herein, includingthe best mode known to the inventors for carrying out the invention. Itshould be understood that the illustrated embodiments are exemplaryonly, and should not be taken as limiting the scope of the invention.

1. A multiple vortex separator for removing solid and liquid waste froma waste stream while withdrawing a substantially moisture-free airstreamunder suction comprising: a housing having an outer wall with an innersurface, a waste inlet for receiving the waste stream, and an enclosedtop with an exhaust port for withdrawing the substantially moisture-freeairstream from the housing; an annular channel along the inner surfaceof the wall defining a first vortex flow path for separating liquid andsolid waste from the waste stream, the annular channel being incommunication with the inlet; and inner and outer nested cones withinthe cylindrical housing defining an inverted conical cavity between thecones, the conical cavity being in communication with the exhaust portand forming a second vortex flow path isolated from the first vortexflow path for separating additional liquid and solid waste from thewaste stream before it is withdrawn from the exhaust port.
 2. Themultiple vortex separator of claim 1 including an exhaust cap removablyclamped atop the housing, where the exhaust port is located in the cap.3. The multiple vortex separator of claim 1 in which the nested conesare mounted directly below the exhaust cap.
 4. The multiple vortexseparator of claim 1 in which a source of suction is connected to theexhaust port for withdrawing the substantially moisture-free airstreamfrom the housing and a waste stream containing liquid and solid waste isconnected to the inlet.
 5. The multiple vortex separator of claim 4 inwhich the multiple vortex separator is disposed in an aircraft and thesource of suction is either a vacuum generator or the differentialpressure between the interior of the aircraft and the outsideatmosphere.
 6. The multiple vortex separator of claim 5 including aconduit for transporting the waste stream from an aircraft toilet to theseparator.
 7. The multiple vortex separator of claim 1 in which thevortex separator is mounted to a waste tank having a drain for removingwaste collected in the tank.
 8. The multiple vortex separator of claim 7in which the vortex separator includes a lower portion that extends intothe waste tank, the lower portion having an outer annular lip and thetank having a corresponding outer annular lip, and the two annular lipsbeing removably clamped together.
 9. The multiple vortex separator ofclaim 1 in which radially disposed vanes are positioned adjacent theentrance to the conical cavity, the vanes being angled about theirradial axes to form angled slots for inducing rotary motion in theairstream passing through the slots into the conical cavity.
 10. Themultiple vortex separator of claim 1 including a barrier extendingbetween the cones forming a top closure of the annular opening, and aninner inverted conical chamber defined by the inner surface of the innercone, the top closure having a port communicating between the invertedconical cavity and the inverted conical chamber.
 11. The multiple vortexseparator of claim 10 including a check valve at the bottom of theinverted conical chamber adapted to open when the multiple vortexseparator is not subject to a suction force.
 12. The multiple vortexseparator of claim 10 including a filter media disposed in the chamberto coalesce moisture in the airstream passing through the chamber. 13.The multiple vortex separator of claim 1 including an exhaust membergenerally centered within the conical chamber having an annular shelfpositioned above the chamber and a tubular portion projecting into thechamber.
 14. The multiple vortex separator of claim 13 including ademister filter disposed across the top opening of the tubular portion.15. The multiple vortex separator of claim 1 including a funnelpositioned below the nested cones having a maximum radius less than theminimum radius of the outer cone for diverting the airstream into theconical cavity.
 16. A multiple vortex separator for removing solid andliquid waste from a waste stream from aircraft toilets or otherreceptacles while withdrawing a substantially moisture-free airstreamunder suction comprising: a housing having an outer wall with an innersurface, a waste inlet for receiving the waste stream, and an enclosedtop with an exhaust port for withdrawing the substantially moisture-freeairstream from the housing; an annular channel along the inner surfaceof the wall defining a first vortex flow path for separating liquid andsolid waste from the waste stream, the annular channel being incommunication with the inlet; inner and outer nested cones within thecylindrical housing defining an inverted conical cavity between thecones, the conical cavity being in communication with the exhaust portand forming a second vortex flow path isolated from the first vortexflow path for separating additional liquid and solid waste from thewaste stream before it enters the exhaust port; an exhaust cap atop thehousing and an exhaust port located in the cap; and a source of suctionconnected to the exhaust port for withdrawing the substantiallymoisture-free airstream from the housing and a waste stream containingliquid and solid waste connected to the inlet.
 17. The multiple vortexseparator of claim 16 in which radially disposed vanes are positionedadjacent the entrance to the conical cavity, the vanes being angledabout their radial axes to form angled slots for inducing rotary motionin the airstream passing through the slots into the conical cavity. 18.The multiple vortex separator of claim 16 including a barrier extendingbetween the cones forming a top closure of the annular opening, and aninner inverted conical chamber defined by the inner surface of the innercone, the top closure having a port communicating between the invertedconical cavity and the inverted conical chamber.
 19. The multiple vortexseparator of claim 18 including a check valve at the bottom of theinverted conical chamber adapted to open when the multiple vortexseparator is not subject to a suction force.
 20. The multiple vortexseparator of claim 18 including a filter media disposed in the chamberto coalesce moisture in the airstream passing through the chamber. 21.The multiple vortex separator of claim 16 including an exhaust membergenerally centered within the conical chamber having an annular shelfpositioned above the chamber and a tubular portion projecting into thechamber opening below the exhaust port in which a demister filter isdisposed across the top opening of the tubular portion.
 22. The multiplevortex separator of claim 16 including a funnel positioned below thenested cones having a maximum radius less than the minimum radius of theouter cone for diverting the airstream into the conical cavity.
 23. Themultiple vortex separator of claim 7 in which no other separator isassociated with the tank for removing the solid and liquid waste fromthe waste stream while withdrawing a substantially moisture-freeairstream under suction.
 24. A method of drawing a substantiallymoisture-free airstream from a waste stream containing liquid and solidwaste comprising: drawing the waste stream containing liquid and solidwaste into an annular channel defining a first vortex flow path in acylindrical housing so that heavier solids and liquids move to theoutside of the housing and fall downwardly while a lighter airstreamcontaining remaining moisture particles migrate to the center of thehousing; and drawing the remaining lighter airstream into an invertedconical cavity in a second vortex flow path isolated from the firstvortex flow path to produce a centrifugal force causing remainingheavier materials to fall through the conical cavity and the remaininglighter airstream to be drawn from the conical cavity.
 25. The method ofclaim 24 in which the remaining lighter airstream is drawn past radiallydisposed angled vanes as it enters the inverted conical cavity.